Hi,
The best way to handle this case is to create two new lists. Then create a standard Newsletter and include the subscription url for both lists. "Click here to confirm your subscription" will subscribe the user to one list...
And "I don't want to be in your mailing list" will subscribe the user to the second list.
Send your Newsletter the standard way and wait...
You will then have users in your new lists so you can see who took the time to click on your links, who opted-in, who refuses to opt-in and who didn't answer! Afterwards run a mass action to delete all users that are on the opted-out list. Or you can send a reminder to those users who are not on both lists, as they didn't respond.
You will have to use the subscription via mail:
https://docs.acymailing.com/setup/subscription-to-your-lists/external-subscription
Or you can use subsciption via url:
https://docs.acymailing.com/setup/subscription-to-your-lists/external-subscription
